Device for heating a heat transfer medium



July 14, 1959 M. J. DE LEoNARDls 2,894,493

DEVICE FOR HEATING yA HEAT TRANSFER MEDIUM Filed June 7, 1956 3 Sheets-Sheet 1 BY f7/mdf ATTORNEYS:

July 14, 1959 M. J. DE LEONARDIS DEVICE FOR HEATING A HEAT 'rRANs1-ER MEDIUM Filed June 7. 195e ,July 14, 1959v M. J. DE LEoNARms 2,894,493

DEVICE FoR HEATING A HEAT TRANSFER MEDIUM 3 Sheets-Sheet 3 Filed June r7, 1956 zw y United States Patent DEVICE FOR HEATING A HEAT TRANSFER MEDIUM Michael J. De Leonardis, Valley Stream, N.Y.

Application June 7, 1956, Serial No. 569,991

2 Claims. (Cl. 122-435) This invention relates to a gas or oil burning furnace or boiler in which a uid medium is heated and circulated to a room, oiice or other space or object which it is desired to heat. While various mediums may be heated and circulated the invention is described herein embodied by a boiler employing Water or steam as the heat transferring medium and having connections through which the water or steam may be circulated through any suitable circulation system. This application is a continuation in part of my copending application Serial No. 179,464 Iiled August l5, 1950, now Patent No. 2,751,892.

An object of the invention is to provide an eicient means for heating a heat transfer medium.

Another object of the invention is to provide a simple, practical and ecient device having a maximum B.t.u. output for the amount of fuel consumed.

Another object of the invention is to provide a device of the above described kind which is of small size in proportion to its heat output.

Another object of the invention is to provide a device of the above described kind which can be operated without any chimney external to the furnace casing.

Other objects of the invention will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combination of elements, arrangements of parts, and in the several steps and relation and order of each of said steps to one or more of the others thereof, all as Will be pointed out in the following description, and the scope of the application of which will be indicated in the following claims.

The invention will best be understood if the following description is read in connection with the drawings, in which,

Figure 1 is a perspective view of a device embodying my invention, partly cut away to show the ow of heated gases over the back and sides of the heat transfer Iiuid compartment;

Figure 2 is a perspective view similar to Figure 1 but further cut away to show the interior of the boiler and especially the heat transfer uid compartment and the path of the heated gases i.e. products of combustion around the projections of the iluid compartment which are above the lire box;

Figure 3 is a front elevation partly broken away of the device shown in Figure 1;

Figure 4 is a rear elevation of the device shown in Figure 1;

Figure 5 is an elevation taken on the line 5--5 of Figure 3;

Figure 6 is a plan view of a horizontal section taken on the line 6-6 of Figure 5;

Figure 7 is a perspective View similar to Figure 1 but showing the baffles which direct gas back and forth over the Isides of the water compartment extended part way over the front of the water compartment, and

Figure 8 is a plan view of a horizontal section through the structure shown in Figure 7.

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As will be seen more clearly from Figure 6, the device comprises a tire-box 10, a first combustion chamber 12 leading upwardly from the re-box; and a boiler space 14 above said rst combustion compartment and comprising part of the compartment 16 for water or other fluid transfer medium that extends entirely around the said rst, or combustion chamber; and a second or lluegas chamber 18 extending around the rear and sides of compartment 16 and communicating at the top with chamber 12, and an insulation chamber 20 extending around the rear and sides of 18 and over the front. Space 14 is above space 12 and separated from it by the horizontal partition 21.

Insulation chamber 20 is defined by walls 20a and 20b extending from base 11 to top wall 15 of the boiler. Compartment 18 is separated from compartment 16 by vertical wall 22, and compartment 16 is separated from chamber 12 by vertica'l wall 23.

The products of combustion pass from the tire-box upwardly in space 12 through an elongated path around the vertically spaced horizontally disposed and inwardly projecting portion 16e-16a of compartment 16. Portions 16a, 16e and 16e project from rear to front within space 12 of the first chamber and portions 1Gb and 16d extend from front to rear within space 12 and substantially overlap said extensions 16a, 16e and 16e although spaced vertically therefrom thus defining anl and communicates at its lower end with compartments v within which the heated gases are passed back and forth over the respective sides of chamber 16 as will be described. Said horizontal projecting portions 16a-16e of compartment 16 extend across the first chamber 12 `and along their lateral margins respectively as well as along their rear margins are open to the main vertically extending compartment 16. Thus each portion 16a-16e opens into three of the four vertically extending portions of compartment 16.

Compartment 16 communicates with space 14, on both side edges of horizontal partition 21 as well as in front of partition 2l. The products of combustion, heated to a high temperature in the lire-box, pass from the re upwardly over the inner face of compartment 16, and around the extensions of said compartment 16e, 16d, 16e, 16h and 16a which are disposed in staggered overlapping relation, to the upper rear end of the portion of space 12 which is abo/ve the horizontally extending portion 16a and below the partition 21 and communicates with compartment 18 which constitutes a continuation of the gas passage provided within space 12. Compartment l18 comprises portions 18a, 18b and 18e. Portion 18a extends over the rear of fluid compartment 16. Portions 18b and 18e overlie the respective sides of compartment 16. Said portion 18a is divided vertically by the partition 24 and the spaces thus provided on the opposite sides of partition 24 communicate respectively with the chambers 18b and 18e at their lower ends through cut outs p at the lower corners of wall 22 which is extended laterally to the wall 2Gb by the lateral extensions 22a and 22b. The ports p are formed by cutting away these lateral extensions 22a and 2217 at the bottom. The gas chamber portions 18b and 18e have horizontal baffles 26a and 26b respectively arranged therein in staggered relation and extending substantially across the full width of the sides respectively so that the products of combustion, after flowing downwardly through divided portion 18a, travel upwardly through an extended path in chamber portions 18b and 18e respectively over the outer Surface of opposite side por tions of chamber 16, to opposite sides of exhaust charnber 28, from which they may be discharged through the small, pipe-like exhaust conduit 30, the diameter of which may be on the order of two to four inches depending upon the size of the heating unit.

Compartment 16 is thus heated on a plurality of surfaces by direct contact with the highly heated products of combustion and a fluid medium therein absorbs heat rapidly and circulates from the inlet and return conduit 32, through chamber 14, from which it passes, in vapor or liquid phase according to the heating system employed, to and through the outlet conduit 34, to the radiators, coils, or other known heat radiating or transferring means employed (not shown) and back to conduit 32.

The structure described above when operated with blower-burner means adjusted as is described herein, provides extremely ecient heating apparatus in which so much of the heat of the heated gases or products of combustion has been successfully transferred to the heat transfer medium in compartment 16 that gases having a temperature in the lire-box on the order of 2400" F. have a temperature on the order of 190 F. in exhaust conduit 30, upon leaving exhaust chamber 28.

In Figures 7 and 8 the structure described above is modified to the extent that the chamber for the heated products of combustion is extended over the front of the chamber 16, and is divided by the vertical partition 2S. TheV baffles 27a and 27h respectively are extended from each side of the boiler around to the front so that the two heated gas streams which are giving up their heat to the fluid transfer means each travel back and forth across a side and part of the front of wall 22 in a continuous path. Thus portion 18h of compartment 18 includes one half of the space between walls h and 22 in front of the front portion of water compartment 16, and portion 18e of compartment 1S includes the other half of the space between said walls 2Gb and 22 in front of the front portion of water compartment 16, the line of division being vertical partition the flue gas chamber as shown in Figure 8, comprises two halves. Each half comprises a part of portion 18a and a side-and-front portion 1S!) or 18C. Each side-and-front portion comprises a side portion and part of the front portion.

The heated gas products of combustion thus iiow from the re box through compartment 12 into the top of portion 18a of compartment 18. Within portion 18a the heated gas is divided by partition 24 into two streams which pass down over the rear portion of the heat transfer medium chamber 16 and through ports p into portions 18h and 13e respectively of the flue gas chamber 18. As best seen in Figure 8 the heat transfer chamber 16 and the ue gas chambers 18a, 18h and 18C have the wall 22 in common. Within each of said portions 18]: and 18C the gases pass back and forth substantially horizontally over one side and half the front of the water compartment 16, rising gradually from beneath the lowest baiie 26 to the exhaust conduit 36. The two streams of gases reach the exhaust conduit from opposite directions by way of exhaust chamber 23. The portions 18]? and 18e of the iiue gas chamber each has a wall in cornmon with a side portion of the heat transfer chamber 16 and a front portion of the heat transfer chamber 16.

In my device the products of combustion ow through an extended path from the fire-box to the exhaust conduit 39 which is of relatively small cross sectional area, and due to the many changes in direction of ow of the products of combustion the rate of ow is slow and gentle. This has two important results. First it produces prolonged contact of the products of combustion with the surface of the compartment 13, without interference due to down draft, and Second, it causes the mixture of fuel and air introduced to the lire box through the blower-burner 36 and the port 37 in the front wall of the furnace, to remain in the re-box long enough to be substantially completely consumed. The slow nonturbulent flow of the products of combustion in my device permits full utilization of the thermal energy of the gases and results in a very ethcient transfer of energy to the fluid transfer medium.

In my device unconsumed fuel passes through a iiue gas passage which is very long compared with the relatively short distance between the fuel inlet and the exhaust port or chimney of the ordinary burner installation, and the very high temperature throughout said long path completes the combustion of any fuel not consumed in the iire-box. The passing of the gases or heated products of combustion first upwardly around the projecting portions 116e, 16d, 16C, 16b and 16a of compartment 16, and then successively down over the rear of the compartment 16 and upwardly over the opposite sides of said compartment provides a very long passage in which flame is supported provided a large portion of air is introduced into the boiler through the oil burner causing a very actively burning flame within the tire box and a stream of flame and products of a combustion travelling gently and slowly through said long restricted path heated to such a high degree that fuel not consumed in the fire box is consumed while travelling through said path, thus effecting a considerable saving over the ordinary type of furnace.

Because no chimney extending directly from the re box upwardly to a point outside the furnace casing is employed there is no draft such as is caused by such a chimney. The mixture of fuel and air is thus held back by atmospheric pressure including the weight of the gas column directly above it and moves along its extended path very slowly in contrast to the rapid flow through and above the fire box of prior art boilers caused by the suction at the top of the chimney which acts to pull the products of combustion. Such suction both works against complete combustion, and materially shortens the time the heated products of combustion remain in contact with the effective heating surfaces inside the standard and prior art boilers.

Plugs 38 have been indicated extending through the insulating outer wall of the furnace. A number of these are provided so that, when removed, ready access may be had to the interior of the compartments through which the products of combustion pass first after leaving the tire box 1i) and the space 12 above the fire box to facilitate cleaning or" this space. A safety pressure valve or plug 40 of an ordinary kind is indicated on top of the furnace as well as the pressure indicator 42 of any well known type. Actual use has shown that very little cleaning is required because of the substantially complete combustion which is accomplished.

It will thus be seen that there has been provided by this invention an apparatus kin which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As various possible embodiments might be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matters hereinbefore set forth or shown in the accompanying drawings is to be inter preted as illustrative and not in a limiting sense.

What I claim is:

1. A boiler or water heater of the class described comprising a plurality of nesting chambers, including a rst innermost chamber comprising a combustion chamber, an intermediate chamber for heat transfer medium, and a third chamber surrounding the intermediate `chamber and forming a ue gas chamber comprising, a rear portion and two side-and-front portions, the rear portion being parallel with and having a wall in common with the rear portion of the intermediate chamber and having means dividing said rear portion vertically into two separate parts, the said side-and-front portions each having a portion parallel with and having a wall in common with a side of the intermediate chamber and a portion parallel with and having a wall in common with one half of the front of the intermediate chamber, a passage for the ilue gas extending from said first chamber to the said rear portion of the ue gas chamber, means providing communication between the said parts of said rear portion of the ue gas chamber and said two side-and-front portions respectively, and vent means communicating with said two side-and-front portions respectively to exhaust flue gas after it has passed from the combustion chamber down the rear portion of the ue gas chamber and up the two side-and-front portions respectively of the ilue gas chamber.

2. A boiler or water heater of the class described comprising, a plurality of nesting chambers, including a rst innermost chamber comprising a combustion chamber, an intermediate chamber for heat transfer medium, and a third chamber surrounding the intermediate chamber and forming a flue gas chamber, means vertically dividing the flue gas chamber into two halves each of which comprises, a part of the rear portion of the flue gas chamber, which is parallel with and has a wall `in common with a portion of the rear of the intermediate chamber, a side portion which is parallel with and has a wall in common with a side of the intermediate chamber and a front portion which is parallel with and has a wall in common with part of the liront of the intermediate chamber, a passage for the flue gas extending from the combustion chamber to both of said halves of the ue gas chamber, means separating the upper portions of the said parts of the rear portion of the iiue gas chamber respectively from the side portions of the said halves of the flue gas chamber, and means in each of the side and the front portions of each of the halves of the Iilue gas chamber for directing the products of combustion from the bottom thereof back and forth therein to the top, and vent means communicating with said side and said front portions at the top.

References Cited in the le of this patent UNITED STATES PATENTS 399,975 Cunningham Mar. 19, 1889 1,349,617 LaFay Aug. 17, 1920 1,609,680 Welsh Dec. 7, 1926 2,751,892 De Leonardis June 26, 1956 

